When all connections timed out on writing, delete them all.

webrtc/p2p/base/p2ptransportchannel.cc

Index: webrtc/p2p/base/p2ptransportchannel.cc
diff --git a/webrtc/p2p/base/p2ptransportchannel.cc b/webrtc/p2p/base/p2ptransportchannel.cc
index 17d224f98293e9981d6111f08213d2cffca3ad94..5e5ba0156e66de9f527609fbe7b2e4e708a5a32f 100644
--- a/webrtc/p2p/base/p2ptransportchannel.cc
+++ b/webrtc/p2p/base/p2ptransportchannel.cc
@@ -1112,9 +1112,11 @@ void P2PTransportChannel::HandleNotWritable() {
   }
 }
 
+// If all connections timed out, delete them all.
 void P2PTransportChannel::HandleAllTimedOut() {
-  // Currently we are treating this as channel not writable.
-  HandleNotWritable();
+  for (Connection* connection : connections_) {
+    connection->Destroy();
+  }
 }
 
 bool P2PTransportChannel::weak() const {